New protein kinase and protein phosphatase families mediate signal transduction in bacterial catabolite repression.
Carbon catabolite repression (CCR) is the prototype of a signal transduction mechanism. In enteric bacteria, cAMP was considered to be the second messenger in CCR by playing a role reminiscent of its actions in eukaryotic cells. However, recent results suggest that CCR in Escherichia coli is mediated mainly by an inducer exclusion mechanism. In many Gram-positive bacteria, CCR is triggered by fructose-1,6-bisphosphate, which activates HPr kinase, presumed to be one of the most ancient serine protein kinases. We here report cloning of the Bacillus subtilis hprK and hprP genes and characterization of the encoded HPr kinase and P-Ser-HPr phosphatase. P-Ser-HPr phosphatase forms a new family of phosphatases together with bacterial phosphoglycolate phosphatase, yeast glycerol-3-phosphatase, and 2-deoxyglucose-6-phosphate phosphatase whereas HPr kinase represents a new family of protein kinases on its own. It does not contain the domain structure typical for eukaryotic protein kinases. Although up to now the HPr modifying/demodifying enzymes were thought to exist only in Gram-positive bacteria, a sequence comparison revealed that they also are present in several Gram-negative pathogenic bacteria.
Galinier
A
A
Institut de Biologie et Chimie des Protéines, Unité Propre de Recherche 412, Centre National de la Recherche Scientifique, F-69367 Lyon Cedex 07, France.
Kravanja
M
M
Engelmann
R
R
Hengstenberg
W
W
Kilhoffer
M C
MC
Deutscher
J
J
Haiech
J
J
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics*; D001426:Bacterial Proteins / Q000378:metabolism; D050260:Carbohydrate Metabolism; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000235:genetics* / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
D001426:Bacterial Proteins; D011494:Protein Kinases; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C030182:phosphocarrier protein HPr; C110847:HPr kinase; D017346:Protein Serine-Threonine Kinases; C110846:YvoE protein, Bacillus substilis; D010749:Phosphoprotein Phosphatases